For many high-tech and Internet-related products, utility to consumers depends in part on the size of the user base, a phenomenon called network externality. A firm with a portfolio of these and other products--that are often asymmetric in their degree of network externality or marginal...

Companies spend hundreds of millions of dollars annually on advertising to build and maintain awareness for their brands in competitive markets. However, awareness formation models in the marketing literature ignore the role of competition. Consequently, we lack both the empirical knowledge and...